The present applicant has already proposed a plate type heat sink described in Patent Literature 1 below.
In this case, numerous slits are punched by press in a metal plate, which is formed into a flat plate, a core is formed by a laminated body of each of plates, and an end plate is disposed at both ends in the lamination direction of the core. Furthermore, each plate has a frame part at the outer periphery thereof, numerous slender ribs are formed integrally between respective slits, and a manifold is disposed at both end parts of each slit. Then, a refrigerant is circulated to each of slits, an exothermic body composed of electronic parts is disposed on the outer surface of the end plate, and the generated heat is removed with the refrigerant.